The present invention relates to a stereoscopic display system, and more particularly to a stereoscopic display system which automatically adjusts the stereoscopic display conditions in accordance with changes of a displayed scene, thereby reducing viewer's discomfort.
Conventionally, a binocular stereoscopic display system has been known in which images for right and left eyes (i.e., images viewed by the right and left eyes, respectively, and hereinafter, referred to as right- and left-eye images or right and left images) are displayed certain on a display screen, i.e., a two- dimensional plane, and both the images are fused by the viewer's brain into a single, three-dimensional image. This system has an essential problem of a discrepancy between accommodation and convergence of eyes. That is, the viewer's eyes are always adjusted so that they are focused on the display screen.
On the other hand, the position of a gazing point on which the viewer's right and left eyes are fixed by eye-ball movement (convergence) depends on the distance between the left and right images on a display screen, normally parallax; thus, in most cases, that point is not located on the display screen.
When such discrepancy is not so large, humans will have the capacity for fusing the right and left images into a single, three-dimensional image. When the degree of discrepancy is large, on the other hand, humans will become unable to fuse the right and left images, or, they will feel fatigue in their eyes. In such a case, it becomes impossible or difficult for them to obtain stereoscopic vision.
Therefore, users used to adjust the stereoscopic display conditions on a trial and error basis to solve the problem. This adjustment work is relatively easy for still images. However, for motion images, it is required to change the setting of the stereoscopic display conditions for each scene because the position of the viewer's gaze point changes with displayed objects of shooting. This is very troublesome. For motion pictures, therefore, the fact is that no change is made to the stereoscopic display conditions.
On the display screen in a stereoscopic display system are often displayed graphical user interface components such as character information, menus, buttons. However, when these graphical user interface components are not adequately displayed in accordance with the change of stereoscopic display conditions, viewers often have strange feeling for the images.
The recent development of the media like digital versatile disks (DVDs) has realized a system in which viewers can freely see the images from various viewpoints. The function for presenting good stereoscopic images are required in such a system. To realize the function, it is strongly desired to solve the above-described problems.